‘The exchange student, right?’

Petra nods. ‘It’s now over twenty-four hours since Yin was taken, give or take a few hours because they don’t know the exact time, but that doesn’t necessarily mean anything bad has happened.’

‘So you think it’s the same guy? They wouldn’t say on the news last night.’

‘Almost definitely.’ Petra lowers her voice. ‘The modus operandi is very similar. I’ve been comparing. In both cases, entry was through a ground-floor window, and family members were tied up. And if I’m right, then the weapon he carried was a gun.’

I try not to raise my eyebrows. Petra is intense. The second bell rings, setting off a chorus of slammed locker doors.

‘Karolina survived because she kept quiet and did what she was told,’ Petra continues when the bell stops. ‘She memorised important details about her surroundings, even though none of it ever got released to the public. Do you know why the police never reveal all the evidence? They keep it under wraps so they can use it to verify—’

Petra breaks off as her best friend Audrey joins us.

‘You ready?’ Audrey doesn’t look at me. If I was asked to name the most aloof girl in our year level, Audrey would win, hands down. She is so above everything I almost admire her for it.

‘Sure.’ Petra gives me a brief, polite smile. She wrestles a music case out of her locker.

‘I need help with Chem.’ Audrey all but clicks her fingers as she walks off, Petra at her heels. The boarders stick together, and Petra especially sticks to Audrey. She’s undeniably the suckerfish and Audrey is undeniably the shark.

DAY 3

Day three of Yin missing, and the student distribution in the quadrangle is out of whack. Normally groups of Year Tens spread out to every part of the courtyard, but today we huddle close on the steps. Even those who are pretending not to take part sit close enough to eavesdrop.

We’re not supposed to have our phones out during school hours, but that’s not possible now. Not when there’s rolling news coverage online, comments and theories and prayers and wishes. Some girls haven’t stopped crying yet, and none of us look like we’ve slept.

My usual lunch spot is the low brick wall above the steps, putting me higher than the rest of the quad, with the dangling branches of a willow screening me. Claire and Milla, Yin’s closest friends, are the epicentre of the gathering. They look incomplete without Yin, a triangle with one of its sides missing. I’d seen them walking around school, heads together, in the library, hauling their musical instruments from one place to the other.

‘They were wearing normal clothes, not police uniforms,’ says Claire. ‘We talked in the lounge room and my parents had to be there.’